Contoured film

ABSTRACT

A water permeable, contoured, polymeric film which is apertured and which contains a pattern of raised areas. The film is formed from elastomeric polymer, preferably a blend of ethylene-vinyl acetate copolymer with incompatible polymer. The numbers of apertures and raised areas contained in the film are such that the ratio of apertures to raised areas is greater than unity. The apertures are preferably distributed in a random manner throughout the raised areas. Processes for forming the film by first aperturing the film and then impressing raised areas into the apertured film are also described. The film may be employed to form the body contacting surface in absorbent devices. The use of the film helps to reduce the phenomenon of wet-back.

The present invention relates to a water permeable, apertured, contouredpolymeric film in which the film is formed from an elastomer. Thecontoured, apertured film of the invention is suitable for use as acover for absorbent devices such as sanitary napkins, incontinence padsand surgical dressings and therefore the present invention also relatesto absorbent devices containing the contoured apertured film and totheir manufacture.

It is desirable that body fluid such as blood, urine or wound exudateentering the absorbent material of an absorbent device such as asanitary napkin, diaper, bed pad, incontinence pad, surgical dressing orbandage should be dispersed throughout the absorbent material in orderto utilise its full absorptive capacity. It is an undesirable feature ofcurrent absorbent device design that absorbed fluid may re-emerge at theentry point or at sites distant from the entry point when localisedpressure is brought to bear on the absorbent device. This phenomenon ofthe re-emergence of absorbed fluid is commonly termed `wet-back`.

The two main methods by which it was sought to reduce wet-back were:

(a) to employ specially designed coverstock, that is the material whichcontacts or may contact the body of the wearer in use and

(b) to employ a separator layer between the coverstock and absorbent.

These improved coverstocks and separator layers were formed essentiallyfrom hydrophobic water permeable films or non-woven fabrics which wereoften coated with surfactant to facilitate passage of the aqueous bodyfluid into the absorbent.

British Pat. No. 1526778 describes an absorbent structure in which thetop sheet (that is the skin contacting sheet) is formed from a fluidimpervious material provided with tapered capillaries in which eachcapillary has a single opening at the apex of the capillary for passageof liquid to the absorbent material. This patent does not disclose orsuggest the use of elastomeric polymers to form the material of the topsheet.

European Patent Application No. 0171268 describes a non-adherent wounddressing which comprises an absorbent in a porous bag. The porous bag isformed from a contoured net of a thermoplastic elastomeric polymericfilm. The film has a regular pattern of geometrically shaped depressionseach of which has a single apical opening.

U.S. Pat. No. 3292619 describes an absorbent dressing comprising a padof absorbent material and a wound contacting surface comprising athermoplastic film which has depressed portions containing a pluralityof openings in which the peripheral edges of the openings are adhered tothe absorbent. This patent does not disclose that the film could be anelastomeric polymer.

It has now been found that by using as a coverstock a water permeable,apertured, contoured, polymeric film formed from elastomeric polymer andin which the ratio of apertures to raised areas of greater than one, anabsorbent device may be manufactured which has good absorbent andwet-back properties. Contoured apertured films formed from elastomericpolymer and in which the ratio of apertures to raised areas is greaterthan one are new. Such films when used to form the body contactingsurface of an absorbent device help to provide a soft feel to thedevice.

Accordingly the present invention provides a water permeable, contoured,polymeric film which comprises a film containing apertures and which hasa pattern of raised areas therein and in which the film is formed fromelastomeric polymer and in which the ratio of apertures to raised areasis greater than unity.

Within the scope of the present invention are films in which the raisedareas may contain different numbers of apertures for example some raisedareas may contain no apertures, some raised areas may contain oneaperture and some apertures may contain more than one aperture but theratio of the total number of apertures to the total number of raisedareas will be greater than unity.

Suitably each raised area will contain at least one aperture andpreferably the ratio of apertures to raised areas will be greater than2.

Suitably the apertures may be distributed throughout the raised areas ina random manner. However, it is possible but less preferred that byjudicious choice of the frequency of the apertures and the raised areas,a film in which the apertures are distributed in a regular mannerthrough the raised areas can be achieved.

Suitably the ratio of apertures to raised areas will be from 2 to 8,more suitably from 3 to 6 and preferably will be between 4 and 5.

Elastomeric polymer is polymer which has a recoverable elastic strain ofat least 20% and more suitably at least 25%, preferably at least 50% andmost preferably at least 100%.

Suitable elastomeric polymers include polyether ester, polyurethanes,styrene-butadiene and styrene-isoprene block copolymers,polyisobutadiene, and blends of ethylene-vinyl acetate copolymers withpolyolefins for example with polystyrene.

Polymeric materials which are suitable for preparing the contouredapertured film of the invention include thermoplastic elastomericpolymers or polymer blends. Favoured elastomeric polymer is a blend ofan ethylene-vinyl acetate copolymer and an incompatible polymer such asa polyolefin and in particular a polystyrene. A particularly preferredelastomeric material is a blend of from 40 to 90 parts by weightethylene-vinyl acetate copolymer and 60 to 10 parts by weight ofpolystyrene and more preferably 60 to 90 parts by weight ofethylene-vinyl acetate copolymer and 40 to 10 parts by weight ofpolystyrene, for example 60 parts ethylene-vinyl acetate copolymer and40 parts high impact polystyrene, 90 parts ethylene-vinyl acetatecopolymer and 10 parts high impact polystyrene. If necessary thepolymeric material may include up to 10% of fillers or whitening agentssuch as titanium dioxide. Thus another preferred elastomeric materialcomprises 90 parts ethylene-vinyl acetate copolymer, 10 parts highimpact polystyrene and 4% by weight of the polymers, of titaniumdioxide.

Other elastomeric material which is suitable for preparing the contouredapertured film of the invention includes elastomeric polyether esterblock copolymers such as Hytrel 4056 (Trade Mark).

Other suitable materials include polyether polyamide block copolymerssuch as those which are designated Pebax (Trade mark). A suitablecopolymer is Pebax 2533 SN 00.

Suitably the apertured film may be provided with contours by pressingagainst a roller or a plate carrying a pattern of raised areassurrounded by troughs of flat areas. The raised areas which give rise tothe contours on the apertured film may be of any shape but raised areaswhich are in the form of truncated square pyramids or hexagons arepreferred. The pattern of raised areas impressed in the apertured filmand the frequency of apertures may be arranged so that any raised areamay contain none, one or more than one aperture, indeed some of theapertures may fall in the land areas between the raised areas in thefilm. This gives a random appearance to the distribution of theapertures amongst the raised areas of the film even though such adistribution may have arisen by impressing a regular pattern of raisedareas on a regular pattern of apertures in the film. This is in directcontrast to the films known in the prior art in which one aperture ispresent at the apex of each depressed area. Aptly each raised area willcontain at least one aperture. In an apt form the pattern of raisedareas and the frequency of apertures may give rise to a substantiallyregular distribution of apertures amongst the raised areas in whichthere are 2 to 4 apertures in each raised area.

Suitably the raised areas impressed in the apertured film will numberper unit area from 4 to 30 raised areas per sq. cm and more suitablywill be 5 to 20 raised areas per sq. cm and preferably 6 to 12 raisedareas per sq. cm for example 8, 9 or 10 per sq. cm.

Suitably the apertured film may contain from 8 to 120 apertures per sq.cm, more suitably will contain from 15 to 90 apertures per sq. cm andpreferably from 30 to 60 apertures per sq. cm.

Suitably the contoured apertured film may have raised areas which haveat least two apertures in the wall of each raised area, more suitablywill have from 2 to 8 apertures per raised area and preferably 2 to 4apertures per raised area.

Favourably the area of each aperture may be from 0.01 sq. mm. to 1 sq.mm. and more favourably 0.1 sq. mm. to 1 sq. mm. and preferably 0.25 to0.75 sq. mm.

Suitably the open area of the apertured film may comprise from 5% to 50%of the area of the film and more suitably 10 to 40% of the area of thefilm.

The elastomeric polymer film used to form the contoured, apertured filmof the invention is usually formed by conventional extrusion methods ofthe polymer or polymer blend. Suitably the thickness of the film whenextruded is from 25 to 200 μm and more suitably is 30 to 150 μm thickand preferably from 35 to 100 μm thick. The thickness will depend tosome extent on the properties of the film as regards strength andsoftness. The contoured apertured film when used in a sanitaryprotection device or a surgical dressing where it contacts the skinshould be soft whilst at the same time being strong enough to be wornwithout tearing.

The contoured apertured film itself will have a thickness as measuredfrom the level of the plane of the non-raised area of the film to thetop of the raised area. Suitably this thickness is from 0.2 to 3mm andmore suitably is 0.5 to 2mm and preferably is 0.5 to 1.5mm. Thecontoured apertured film when used in an absorbent device thereforeprovides separation of the absorbent from the wearer.

The contoured apertured films of the present invention are particularlysuitable for use in absorbent devices. Absorbent devices when usedherein include sanitary napkins, diapers, incontinence pads, and in asomewhat different area, surgical dressings. In these devices thecontoured apertured film comprises at least a part of the surface whichmay at some time in use contact the skin of the wearer. The filmnormally provides a dry surface and when placed under pressure serves torestrict passage of absorbed fluid whereby the wearer's skin remains ina substantially dry condition. The raised areas are arranged to faceaway from the body of the wearer and towards the absorbent material.

In a second aspect therefore the present invention comprises anabsorbent device comprising an absorbent material and a water permeable,contoured, apertured film formed from elastomeric polymer as hereinbefore defined.

Suitably the absorbent device is in the form of a sanitary napkin ordiaper in which at least the body facing surface of the device includescontoured apertured film of the invention. Suitably the whole of thebody facing surface comprises a contoured apertured film. Most aptly thedevice is a sanitary napkin. The sanitary napkin may have theconventional structure which the skilled worker would recognise as usualin the art, that is a liquid pervious body facing layer, absorbentmaterial and a fluid impermeable backing layer. The facing layer andfluid impermeable backing layer may be heat sealed around their edges toenclose the absorbent material.

Alternatively the contoured apertured film may extend around the wholeof the absorbent material to overlap on the garment facing side and theedges adhered by for example a hot melt or pressure sensitive adhesive.In this embodiment a fluid impermeable layer may be placed at leastbetween the garment facing side of the absorbent and apertured film. Inyet a further alternative the contoured apertured film may form a stripin part of a larger piece of film whereby the contoured and aperturedportion of the film forms the body contacting surface and the adjacentnon-apertured and optionally non-contoured portions of the film arewrapped around the remainder of the absorbent material to provide thefluid impermeable wrapper.

The absorbent material used in the invention can be any of the absorbentlayers used in conventional hygienic absorbent pads. Suitable absorbentmaterials for such layers include comminuted/fluffed wood pulp, cardedcotton webs, viscose rayon fibres, tissue wadding, grafted cellulosesuper absorbents, polymeric super absorbents or mixtures thereof. Theabsorbent layer can optionally contain an insert such as a tissuewadding to aid fluid distribution within the layer.

In a further embodiment of this aspect of the invention the absorbentdevice may be in the form of a surgical dressing.

The contoured apertured film may be prepared as follows: a film isformed from elastomeric material by, for example, conventional blendingand/or extrusion methods. The film may also contain fillers, whiteners,plasticisers, surfactants and the like to aid processing and to providesatisfactory surface characteristics and appearance to the finishedfilm. The film may then be apertured using the normal methods used inthe art including flame perforation and pin moulds with heated ornon-heated pins. In one method the film may be placed against a pinmould and covered by a plain polyethylene film. The three layer sandwichis then compressed where upon the pins of the pin mould aperture theelastomer film removing a piece of that film having the area of the pin.These pieces of film adhere to the polyethylene film. On removal of thecompressive force, the polyethylene film along with the small pieces ofelastomeric film are then removed to reveal a substantially flatapertured film of the elastomeric polymer.

The apertured film may then be contoured by placing it on the surface ofa thermoplastic film, such as a polypropylene film, which has discreteraised areas for example 10 raised areas per sq. cm. The raised areasmay be coated with a silicone release agent to facilitate removal of theformed contoured apertured film. The raised areas may be of any shapebut either square truncated pyramids or hexagonal shapes are preferred.The apertured film is contoured by compressing it against the raisedareas of the film. Usually a resilient material, such as a foam, ispresent on the other side of the apertured film. The compression may beprovided by a conventional press or by passing between the nip of a tworollers. It is possible that additional apertures may be placed in thealready apertured film at this stage. These additional apertures areformed in the film at the tip of each of the raised areas in thethermoplastic film. The conditions of temperature and pressure used inthe process will depend upon the properties of the elastomeric filmemployed. After this treatment the contoured apertured film may bepeeled off the thermoplastic film. The size of the raised areas and thepattern of bosses employed will vary depending upon the size ofapertures in the elastomeric film. The raised areas of the film may beadapted in size so that at least two apertures fall in the walls of eachof the raised areas formed in the apertured film during the compressionprocess.

Alternatively the apertured film may be contoured by passing it betweentwo rollers one or both of which may have a pattern of raised and/ordepressed areas on their surface. The rollers may be heated to asuitable temperature to assist in contouring the film. In one methodonly one roller carries a pattern of raised areas on its surface. Theother roller, the smooth roller, preferably has a soft resilient surfaceof rubber or foam which allows the raised areas on the other roller,which is normally made of hard material such as metal, to press into andpermanently deform the apertured film. A preferred method is to use tworollers which have an intermeshing pattern of raised and depressed areason their surface.

In a further aspect therefore the present invention provides a processfor the preparation of a water permeable, contoured film formed fromelastomeric polymer which film contains apertures and has a pattern ofraised areas therein, which process comprises forming apertures in afilm of the elastomeric polymer and then compressing the apertured filmagainst a pattern of raised and/or depressed areas whereby a pattern ofraised areas is impressed in the apertured film, the number of aperturesand raised areas being such that the ratio of apertures to raised areasis greater than unity.

EXAMPLE 1

A polymer blend containing 60 parts by weight of ethylene-vinyl acetatecopolymer (containing 28% vinyl acetate) and 40 parts by weight of highimpact polystyrene and 4% by weight of the polymer of titanium dioxidewas formed by mixing the polymers in a blade mixer heated to 165° C. for4 minutes. The resultant mix was removed from the mixer and formed intoa sheet using a heated roll mill. This sheet was allowed to cool andthen granulated in a Masson cutter.

A film was made from the polymer blend granules using a BrabenderExtrusiograph extruder (length to diameter screw ratio of 25:1) drivenby a Brabender PLE 651 Plasticorder and extruding the mixture through a150mm film die into a nip of a two roller casting unit placed near thedie. The resultant film had a thickness of 125 μm.

The film was taken and apertures formed in it by compression between apin mould and a flat rigid film of polyethylene. On removal of thecompressive force and the polyethylene film, a flat apertured film ofthe elastomeric polymer was obtained. The general configuration of theapertures was square having a side of approximately 0.5mm and hence anarea of 0.25 sq. mm, the open area was 19%.

The apertured film was then placed on the embossed surface of apolypropylene sheet, which had a pattern of raised discrete, hexagonalbosses on that surface. A resilient polyurethane foam was placed overthe apertured film. This sandwich was subjected to pressure and heat,80° C. for 5 minutes. The polymer blend film had been formed into waterpermeable, contoured, apertured film material under the influence of theheat and pressure and could then be removed from the embossed surface ofthe plastics sheet.

An absorbent core (width 60 mm, length 216 mm) of comminuted fluff pulp(6.6 g), having a central layer insert of folded tissue wadding wasplaced centrally onto a strip of the apertured film (width 70 mm, length240 mm) so that the openings in the film were in contact with theabsorbent core. A film of liquid impervious film, polyethylene, wasplaced over the other side of the absorbent core and heat sealed aroundits edges to the apertured film is that the absorbent core is sandwichedbetween the two films.

A portion or portions of the outer facing surface of the liquidimpervious film may carry a pressure sensitive adhesive layer covered bya release paper whereby in use the absorbent device in the form of asanitary napkin may be adhered to a garment of the wearer.

EXAMPLE 2

Contoured apertured film was formed in a similar manner to thatdescribed in Example 1. Prior to preparing the sanitary napkin theembossed surface of the apertured film was spray coated with an acrylicemulsion adhesive at a weight per unit area of 5 gsm (approx) so thatwhen the absorbent core was placed in contact with the apertured film itwas adhered thereto. The absorption of fluid by the absorbent core wasnot impaired by the adhesive.

EXAMPLE 3

An apertured film was formed in a similar manner to that described inExample 1 except that instead of using a polymer blend to form the film,the film was formed from an elastomeric polyetherester, Hytrel 4056, andthe film was 85 μm in thickness. After aperturing and contouring thefilm maybe used to form the body contacting surface of a sanitarynapkin.

EXAMPLE 4

A polymer blend containing 40 parts by weight of ethylene-vinyl acetatecopolymer (containing 18% vinyl acetate content), 40 parts by weight oflow density polyethylene, 20 parts by weight of polystyrene, 3% byweight of the polymer of titanium dioxide and 1% by weight of acompatible surfactant was formed in a similar manner to that describedin Example 1.

An apertured film was prepared from this polymer blend by extruding itbetween the nip of two rollers, one engraved with grooves in an annulardirection and the other engraved with grooves in an axial direction, theextruded film was stretched at a ratio of 2:1 in the machine directionand perforated using a pin mould perforation method. The resultant flatapertured film had a mass weight per unit area of 40 gsm, contained90-100 apertures per sq cm which were ellipsoidal in shape having anaperture area of 0.27 sq mm and the film had an open area of 23%.

The apertured film was impressed with raised areas by passing it betweenthe nip of two rollers one of which was engraved with square pyramidalembossments and the second a plain roller covered with a resilientcoating of paper.

A sanitary napkin was prepared in a similar manner to that described inExample 1 in which the contoured apertured film formed the bodycontacting surface of the napkin.

EXAMPLE 5

A water permeable, contoured apertured film was prepared in the mannerdescribed in Example 4.

An absorbent core (width 60 mm, length 216 mm) of comminuted fluff pulp(6.6 g), having a centrally placed layer insert of folded tissue waddingwas placed centrally onto a strip of the apertured film (width 150 mm,length 240 mm) so that the openings in the film were in contact with oneface of the absorbent core. A film of liquid impervious polyethylene wasplaced over the exposed face of the core so that the surface of the coreand a portion of the longitudinal side edges of the core were covered bythe polyethylene. The apertured film was then folded around theabsorbent core so that the edges overlapped and the edges were thensealed together and to the polyethylene film by means of a pressuresensitive adhesive. The polyethylene film formed a fluid impermeablebarrier layer between the absorbent layer and the apertured, contouredfilm. The ends of the folded films were heat sealed so that theabsorbent core was completely enclosed.

EXAMPLE 6

A water permeable, contoured, apertured film was prepared in a mannersimilar to that described in Example 4 except that only a strip 60 mm inwidth on the contoured film comprises raised areas containing apertures,the remainder of the film is contoured but non apertured.

An absorbent core of the composition and dimension described above wasplaced over the 60 mm strip of apertured contoured film. The remainderof the contoured film was folded around the absorbent core so that theedges overlapped. The edges were then adhered to each other with apressure-sensitive adhesive and the ends heatsealed together to enclosethe absorbent core. In this sanitary napkin the unapertured contouredfilm formed a liquid impermeable barrier layer over the garment facingsurface of the absorbent core.

EXAMPLE 7

A water permeable, contoured, apertured elastomeric film was prepared ina manner similar to that described in Example 4 except that only a strip60 mm in width in the film was in the form of a contoured aperturedfilm, the remainder of the film was plain, uncontoured, unapertured andwater impermeable.

An absorbent core of the composition and dimensions described above wasplaced over the 60 mm strip of apertured, contoured film. The remainderof the film was folded around the absorbent core so that the edgesoverlapped and were sealed together using a pressure sensitive adhesive.The ends of the film were heat sealed together so that the absorbentcore was totally enclosed. The contoured, apertured film formed the bodycontacting surface of the absorbent device and the remainder of the filmprovided a fluid impermeable barrier layer.

Fluid Wet-Back Test

Sanitary napkins prepared according to Example 1 were subjected to afluid wet back test which was carried out in the following manner.

A 2 Kg flat weight (dimensions 10×5 cm) was placed on the napkin andallowed to remain in placed for 2 minutes and then removed. 5ml of 1%saline solution coloured with lissamine green dye was delivered onto thecentre of the napkin by means of a syringe pump at a rate of 1 ml/minand at a height of 1 cm above the napkin surface formed by the contouredapertured film. A pre-weighed stack of filter papers (Whatman No. 1filter papers) were then placed over the wetted area of the towel and a2 Kg flat weight (dimensions 10×5 cm) placed on the filter papers. After1 minute, the filter papers were removed and weighed. The wet backexpressed as grams of fluid was then calculated from the difference inweight of the filter papers before and after compression against theabsorbent device. The results are the average of tests in five samples.

    ______________________________________                                        Sample           Wet Back                                                     ______________________________________                                        Example 2        0.03 g                                                       Example 4        0.02 g                                                       Commercial napkin                                                                              0.98 g                                                       ______________________________________                                    

I claim:
 1. A water permeable, contoured polymeric film which comprisesa film containing apertures and which has a pattern of raised areastherein, in which the film is formed from elastomeric polymer and inwhich the ratio of apertures to raised areas is greater than unity.
 2. Afilm according to claim 1 in which the apertures are described in arandom manner throughout the raised areas.
 3. A film as claimed ineither of claims 1 or 2 in which each raised area contains at least oneaperture.
 4. A film according to claim 3 in which the ratio of aperturesto rasied areas is greater than
 2. 5. A film according to claim 4 inwhich the film contains from 4 to 30 raised areas per sq. cm and eachraised area contains from 2 to 4 apertures.
 6. A film according to claim1 in which the film contains from 8 to 120 apertures per sq. cm and hasan open area comprising from 5% to 50% of the area of the film.
 7. Afilm according to claim 1 in which the area of each aperture is from 0.1sq. mm to 1 sq. mm.
 8. A film according to claim 1 in which thethickness of the contoured film is from 0.2 to 3 mm.
 9. A film accordingto claim 1 in which the elastomeric polymer has a recoverable elasticstrain of at least 25%.
 10. A film according to claim 1 in which theelastomeric polymer is a blend of from 40 to 90 parts by weight ofethylene-vinyl acetate copolymer with 60 to 10 parts by weight ofincompatible polymer.
 11. An absorbent device for body fluids comprisingabsorbent material and a body facing surface wherein at least a portionof the body facing surface comprises a water permeable, contouredpolymeric film which comprises a film containing apertures and which hasa pattern of raised areas therein, in which the film is formed fromelastomeric polymer and in which the ratio of apertures to raised areasis greater than unity.
 12. An absorbent device according to claim 11which is in the form of a sanitary napkin.
 13. A process for thepreparation of a water permeable, contoured film formed from elastomericpolymer which film contains apertures and has a pattern of raised areastherein, which process comprises forming apertures in a film of theelastomeric polymer and then compressing the apertured film against apattern of raised and/or depressed areas whereby a pattern of raisedareas is impressed in the apertured film, the number of apertures andraised areas being such that the ratio of apertures to raised areas isgreater than unity.
 14. A process according to claim 13 in which theapertures are formed using a pin mould.
 15. A process according to claim13 in which the film after being apertured is compressed between aroller which carries a pattern of raised areas on its surface and asmooth roller having a resilient surface.
 16. A process according toclaim 13 in which the film after being apertured is compressed between apair of rollers which have an intermeshing pattern of raised anddepressed areas on their surface.
 17. An absorbent device according toclaim 11 in which the whole of the body facing surface of the devicecomprises a contoured apertured film.
 18. An absorbent device accordingto claim 11 in which the apertures are distributed in a random mannerthroughout the raised areas of the film.
 19. An absorbent deviceaccording to claim 11 in which each raised area of the film contains atleast one aperture.
 20. An absorbent device according to claim 19 inwhich the ratio of apertures to raised areas in the film is greater than2.
 21. An absorbent device according to claim 20 in which the filmcontains from 4 to 30 raised areas per sq. cm and each raised areacontains from 2 to 4 apertures.
 22. An absorbent device according toclaim 11 in which the film contains from 8 to 120 apertures per sq. cmand has an open area comprising from 5% to 50% of the area of the film.23. An absorbent device according to claim 11 in which the area of eachaperture is from 0.1 sq. mm to 1 sq. mm.
 24. An absorbent deviceaccording to claim 11 in which the thickness of the contoured film isfrom 0.2 to 3 mm.
 25. An absorbent device according to claim 11 in whichthe elastomeric polymer has a recoverable elastic strain of at least25%.
 26. An absorbent device according to claim 11 in which theelastomeric polymer is a blend of from 40 to 90 parts by weight ofethylene-vinyl acetate copolymer with 60 to 10 parts by weight ofincompatible polymer.
 27. An absorbent device for body fluids comprisingabsorbent material and a body facing surface wherein at least a portionof the body facing surface comprises a water permeable, contouredpolymeric film which comprises a film containing apertures and which hasa pattern of raised areas therein, in which the film is formed fromelastomeric polymer and in which the ratio of apertures to raised areasis from 2 to
 8. 28. An absorbent device according to claim 11 which isin the form of a diaper.
 29. An absorbent device according to claim 11which is in the form of a surgical dressing which comprises an absorbentand a surface which in use contacts the skin wherein the surfacecomprises a water permeable, contoured polymeric film which comprises afilm containing apertures and which has a pattern of raised areastherein, in which the film is formed from elastomeric polymer and inwhich the ratio of apertures to raised areas is greater than unity.